1. Field of the Invention
The present invention relates to a plate feeding apparatus and method for feeding plates stored in a plurality of cassettes to an image recording apparatus for recording images on the plates.
2. Description of the Related Art
Four color plates of Y (yellow), M (magenta), C (cyan) and K (black) are used to produce color prints. Such plates are prepared by using an image recording apparatus called a CTP (Computer-To-Plate) machine which records images directly on the plates such as PS plates (Persennsitized Plates). This image recording apparatus records desired images on the plates by irradiating the plates with light beams modulated according to respective image signals of Y (yellow), M (magenta), C (cyan) and K (black).
A plate feeding apparatus for automatically feeding the plates to the image recording apparatus includes a cassette for storing the plates, and a transport mechanism for transporting the plates from the cassette to the image recording apparatus.
Where, for example, the image recording apparatus records images on plates of various sizes, or consecutively records images on a great number of plates, the plate feeding apparatus, preferably, is constructed for automatically feeding the plates from a plurality of cassettes to the image recording apparatus.
In a conventional measure taken to meet such a requirement, a plurality of plate feeding apparatus each including a cassette and a transport mechanism are installed and connected to the image recording apparatus. Plates are automatically fed from the plurality of cassettes to the image recording apparatus.
However, where the above construction is employed, the plurality of plate feeding apparatus and the image recording apparatus constitute an enlarged overall system that requires an extensive installation space. In addition, is the system per se is complicated and costly.
An object of the present invention, therefore, is to provide a plate feeding apparatus and method for feeding plates from a plurality of cassettes to an image recording apparatus easily without requiring an enlarged construction.
The above object is fulfilled, according to the present invention, by a plate feeding apparatus for feeding plates stored in a plurality of cassettes to an image recording apparatus for recording images on the plates, comprising:
(1) a plurality of cassettes stacked vertically;
(2) a slide mechanism for horizontally moving one of the cassettes;
(3) a lift mechanism for supporting and vertically moving the one of the cassettes horizontally moved by the slide mechanism, to a plate feed position for feeding plates to the image recording apparatus; and
(4) a transport mechanism for transporting the plates to the image recording apparatus from the one of the cassettes moved to the plate feed position by the lift mechanism.
This plate feeding apparatus is constructed to horizontally slide and then vertically move a cassette to place the cassette in the plate feed position for feeding plates to the image recording apparatus. Thus, the plate feeding apparatus has a compact construction, and yet is capable of feeding plates from a plurality of cassettes to the image recording apparatus with ease.
In a preferred embodiment of the invention, the slide mechanism includes a first guide for horizontally guiding each of the cassettes, a first pinion rotatable by a motor, and a rack attached to a wall of each of the cassettes and meshed with the first pinion.
Preferably, the lift mechanism includes a second guide for horizontally guiding one of the cassettes, the first guide and the second guide being aligned by a vertical movement of the lift mechanism per se when the cassette is moved horiontally.
The lift mechanism may further include a second pinion rotatable by a motor, the first pinion and the second pinion being spaced from each other by a distance less than a total length of each rack when the first guide and the second guide are aligned.
In another preferred embodiment, the plate feeding apparatus further comprises a strip sheet discharge mechanism for discharging strip sheets each disposed between an adjacent pair of the plates from the cassette placed in the plate feed position.
In another aspect of the invention, a plate feeding apparatus for feeding plates stored in a plurality of cassettes to an image recording apparatus for recording images on the plates, comprises:
(1) a multiple cassette station having a plurality of cassettes stacked vertically;
(2) a slide mechanism for horizontally moving one of the cassettes stacked in the multiple cassette station, the slide mechanism including:
first guides corresponding in number to the cassettes for horizontally guiding the cassettes;
racks each attached to a wall of one of the cassettes; and
first pinions corresponding in number to the cassettes and each rotatable by a motor while being meshed with one of the racks;
(3) a lift mechanism for supporting and vertically moving the one of the cassettes horizontally moved by the slide mechanism, to a plate feed position for feeding plates to the image recording apparatus, the lift mechanism including:
a lift member vertically movable by a motor;
a second guide attached to the lift member to be movable into alignment with one of the first guides when the one of the cassettes is moved horizontally by the slide mechanism, to cooperate with the one of the first guides for horizontally guiding the one of the cassettes; and
a second pinion attached to the lift member and rotatable by a motor while being meshed with one of the racks, the first pinion and the second pinion being spaced from each other by a distance less than a total length of each rack when one of the first guides and the second guide are aligned; and
(4) a transport mechanism for transporting the plates to the image recording apparatus from the one of the cassettes moved to the plate feed position by the lift mechanism.
In a further aspect of the invention, there is provided a plate feeding method for feeding plates stored in a plurality of cassettes to an image recording apparatus for recording images on the plates, by sliding the cassettes with a slide mechanism and then vertically moving the cassettes with a lift mechanism. This plate feeding method comprises:
(1) a plate depositing step for depositing plates in a plurality of cassettes stacked vertically;
(2) a sliding step for horizontally moving one of the cassettes in a multiple cassette station, the one of the cassettes having a plate to be used for recording images;
(3) a vertically moving step for vertically moving, with the lift mechanism, the one of the cassettes having been moved horizontally, to a plate feed position for feeding the plates to the image recording apparatus; and
(4) a plate transporting step for picking up the plate, with a transport mechanism, from the one of the cassettes placed in the plate feed position, and transporting the plates to the image recording apparatus.
Other features and advantages of the present invention will be apparent from the following detailed description of the embodiments of the invention.